Here's the proper way to delete the Windows.old and $Windows.BT folders: 1  Click Start and type in disk cleanup (no quotes). Wait for the Disk Cleanup utility to show up in the Start menu and click it. 2  A window will appear asking you which hard drive you want to clean up. Choose the C drive (which is default) and click OK.
The A-and B-type HCs are very similar in appearance in the rabbit retina too. Other species may have more than two types of horizontal cell and often these other types are concerned with color coding (see chapter on Horizontal cells by Perlman et al., webvision).
The human retina contains about 120 million rod cells and 6 million cone cells. The number and ratio of rods to cones varies among species, dependent on whether an animal is primarily diurnal or nocturnal. Certain owls, such as the tawny owl, have a tremendous number of rods in their retinae.he rods are narrower than the cones and distributed differently across the retina, but the chemical process in each that supports phototransduction is similar. A third class of photoreceptor cells was discovered during the 1990s: the photosensitive ganglion cells.